(1) An advertisement offering the reward only for one of several contestants who has performed the act in the manner deserving the highest credit shall be effective only if a certain period of definite duration is stipulated for the contest.
(2) Where of paragraph (1), the decision as to whose performance deserves the highest credit shall be made by the person designated in the advertisement. If no such designation has been made in the advertisement, the decision shall be made by the advertiser himself or herself.
(3) A decision that no performance deserves the highest credit among the contestants shall be impermissible; provided, this shall not be the case where declaration of a different intention from the above exists in the advertisement or the standards of the decision has been stipulated by the nature of the advertisement.
(4) No contestant may raise objection to the decision mentioned in paragraphs (2) and (3).
(5) If two or more persons are judged to have performed the act with the same highest credit, the provisions of Article 676(2) shall apply mutatis mutandis.